Nucleation and growth kinetics of AlN films on atomically smooth 6H-SiC (0001) surfaces

Nucleation and growth kinetics of AlN films on atomically smooth 6H-SiC (00 01) surfaces, which were obtained by HCl etching at elevated temperatures p rior to growth, were investigated. The surface morphology and the defect de nsity of AlN films on such surfaces were significantly improved compared to those on as-received SiC surfaces. This is due to enhanced diffusion lengt h and reduced incoherent boundaries at the coalescence regions of the AlN i slands. AlN nuclei on the as-received SiC surface were crystallographically misaligned and thus induced incoherent boundaries at the coalescence stage , resulting in the delay of the two-dimensional growth mode transition and defect formation in AlN films. (C) 2001 American Institute of Physics.